The present invention relates to a method for manufacturing an insole, and more particularly to one for manufacturing an air-pervious insole.
Insoles for sport shoes can be categorized into two types, i.e. ventilating hole-provided ones and non-ventilating hole-provided ones. The method for manufacturing the latter includes (1) obtaining an elastic base piece of a foamed material, (2) adhering a cloth layer on the base piece, (3) baking the cloth layer-adhered base piece to soften the base piece, (4) molding the baked cloth layer-adhered base piece in a cooling mold, and (5) cutting the cooled and molded piece to obtain an insole which is not ventilating hole-provided so that the foaming material to be used to obtain the elastic base piece must be air-pervious, e.g. the PU, and cannot be air-impervious, e.g. the EVA in order that a foot will not easily sweat to prevent the foot from producing a bad odor or becoming an athlete's foot.
Generally speaking, there are two methods for manufacturing the former. The first one includes in addition to the above five steps a step of perforating the obtained insole which will thus include on the cloth layer perforated holes which must have a relatively small size in order that the foot, regardless of wearing a sock or not, stepping thereon will not feel uncomfortable. The second one includes (1) baking directly the obtained elastic base piece, (2) molding and perforating the baked base piece, (3) adhering a cloth layer on the perforated base piece, and (4) cutting the cloth layer-adhered base piece to obtain an insole which includes on the cloth layer no holes, however, adhering the cloth layer to the molded base piece is difficult and troublesome.
Upon shaping, it is the inherent characteristic of the foaming material that the foamed piece will form on all of its surface a film layer having a hardness and a materiality better than those of the foamed piece at any point other than the film layer. The base piece in any of the above described manufacturing methods can hardly contain the film layer since the base piece is sliced from a relatively thick foamed piece, so that the manufactured insole is easily deformable to thin the base piece to reduce the shock absorptivity and to decrease the holed percentage to deteriorate the air-perviousness which originates from the fact that the density of the thinned elastic base piece is increased for a non-ventilating hole-provided insole and the bore of the ventilating holes of the thinned base piece is reduced for a ventilating hole-provided insole.
In addition, the ventilating holes of the ventilating hole-provided insole are not provided on the arcuate portion and the edges of the insole where to perforate is difficult and thus the air-perviousness of the insole is not ideal.
It is therefore tried by the Applicant to deal with all of the above problems encountered by the prior art.